Phonation is a component of speech communication with a highly complex interplay of physiological and physical properties. Phonation is the vibratory system in the larynx that changes air flow from the lungs into sound in the throat. The process of vocal fold vibration and the conversion of air flow into sound is insufficiently understood for the purposes of making precise diagnostic decisions in the voice clinic, targeting optimal intervention strategies for voice problems, and achieving high quality articulatory speech synthesis. The long-range goal of this research program is to develop an efficient and highly effective computer model of phonation that takes into account the tissue and flow-acoustic dynamics for both normal and pathological laryngeal conditions. This continuation application focuses on the details of the basic physics dealing with the flow-acoustic interactions and driving intraglottal pressures by using various physical, computational, and tissue models of phonation. The aims are to 1) extend phonatory modeling to three dimensions with greater geometric complexity, 2) gain a thorough understanding of the aerodynamics and aeroacoustics for steady and pulsatile flows in rigid and moving-wall laryngeal airways, 3) develop detailed predictive models to explain the flow physics of phonation, in parallel with simpler models that are computationally efficient and clinically applicable, and 4) determine the effects of glottal jet flow for normal and pathological conditions of the glottis using an in-vivo canine model. The three types of models (physical, computational, and tissue) are used to cross-validate new information that bridges between basic modeling and real larynx phonation. This research program is a collaboration among laboratories at Bowling Green State University, Purdue University, the University of Toledo, and Washington University in Saint Louis.